Adjustable shelf



FIG. 1 is a top plan view of an adjustable shelf showing my new design,

FIG. 2 is a front elevational view thereof,

FIG. 3 is a bottom plan view thereof,

FIG. 4 is a left side elevational view thereof,

FIG. 5 is a front and left side perspective view thereof,

FIG. 6 is a front and left side perspective view of an adjustable shelf, and

FIG. 7 is a front and left side perspective view of an adjustable shelf showing my new design according to a third embodiment thereof. 

The ornamental design for an adjustable shelf, as shown. 